Equipment costs are crazy $$$$
my setup is probably ~$10k.. and you are always upgrading/adding hardware)

Monthly costs are crazy $$$
I use about $150 in salt a month, $75 in additives (calcium, alkalinity, and other supplements), $50 in water filtration, ~$25 in coral/fish food... then other odd's and ends. Then you probably need to add in electricity costs (lights, heaters, filters, equipment)

Coral is $$$.. a small .75" piece can cost $100+ (the goal is to cover your tank with it).

You need fish to keep the ecosystem going.. and due to Hawaii putting a ban on hobby fish the prices have gone crazy.

A fish that was $40 last year is now $400.


The two top rules in keeping a reef tank are:
Never add up how much you spend
Never tell your wife how much you spend.